I just purchased a (effin expensive i might add) DVR controller, 16 channel full 25fps per channel recording to 1-8 hard disks

Now from what I understand, an RS485 connector is used (which my DVR has ONE of) to connect to these ptz cameras, but I was wondering what if I wanted 4 or so cameras to have PTZ functionality, how do I connect to them using only one RS485 connector?

I scoured the web for maybe some sort of multiplexer, but nothing helpful comes up.

Can anyone point me in the right direction? It would be incredibly appreciated.

PTZ's are serial devices. So you do one of a few things. Wire them in a seris, or wire them to a terminal block then wire the cameras to that in a star pattern. Before hanging the cameras you'll want to set the camera ID. And terminate the last one.

what DVR and what PTZ is it??